PTGS2 and colorectal adenocarcinoma: The COX-2 overexpression has been reported in several human cancers that include breast (23), lung (33), skin (34), esophagus (35), pancreas (36), prostate (37), bladder (38), stomach (39), oral cavity (40, 41), and colorectal adenocarcinoma (19, 42) (Table 1).